1. Field of Invention
This invention relates to trailer hitches, specifically to the method of connecting and disconnecting a trailer to a towing vehicle.
2. Description of Prior Art
Previous to our invention, most trailer hitches were designed in such a way that they required a significant amount of manual intervention to operate.
In most known prior art hitches, the method for facilitating coupling was a receiving unit with an alignment hole, mounted to the rear underside of the towing vehicle, which accepted a shank portion of a head assembly. The head assembly comprised a protruding shank with a corresponding hitch pin hole and a ball mount with a ball. The shank portion of the head assembly was manually inserted into the receiver, aligned, and affixed by means of a hitch pin. The towing vehicle was then backed up to the trailer, which was supported by a leveling jack. The towing vehicle was maneuvered until the ball of the head assembly was aligned under the ball socket of the trailer tongue, then the tongue was lowered, and the ball socket was manually locked and the units were coupled.
An electrical cord was then manually connected between the two vehicles to supply electrical power from the towing vehicle to the trailer, for turn signals, running, brake, and backup lights, and to keep the battery of the trailer charged.
In weight distributing hitch systems, spring bars were used to provide proper load transference between the towing vehicle and the trailer by use of tensional force. The forward ends of the spring bars were inserted into spring bar sockets of the head assembly and were rotated rearwardly. The rearward ends of the spring bars had chains welded to their topside which were pulled upward and placed onto a hook which was part of a bracket clamped to the rearward end of the trailer tongue frame. To obtain proper tension and load-transferring capabilities, the chains were tensioned by a hookup handle manually pushed onto the end of the hook and forced upward. This raised the chains and increased stress on the spring bars which equally distributed the weight of the trailer to the towing vehicle. The brackets and chains were locked into place and secured by a wire retaining clip.
To disconnect, the leveling jack was lowered to support the weight of the trailer. The wire retaining clip was then disengaged. The hookup handle was manually pushed onto the chain hook of the bracket and pulled downward to release the chains, thereby relaxing the tension on the spring bars. The chains were then removed from the chain hook of the bracket and the spring bars were rotated forwardly and dropped out of the head assembly. The ball socket of the trailer tongue was unlocked and the trailer was raised slightly by use of the leveling jack, exposing the ball. The electrical cord was manually disconnected from the towing vehicle, leaving the towing vehicle free to move forward. The hitch pin was pulled from the receiver and the head assembly was removed and stored with the spring bars.
U.S. Pat. No. 2,062,788 to Jacob, Dec. 1, 1936 shows a hitch with a pair of swinging latch and lock dogs affixed to the trailer tongue frame for engagement with a ball-mounted probe on the towing vehicle. In order to couple trailer and towing vehicle, a manual, four-step procedure was required for moving the dogs to a released position, to an automatic latching position, and to a positive locking position. A manual procedure was also required in order to uncouple the units. The electrical connection between the trailer and the towing vehicle was done manually. There was no accommodation for weight distribution.
U.S. Pat. No. 2,952,475 to Reese, Sep. 13, 1960 shows a hitch with a weight distributing (load transferring) system using spring bars, draw chains, and hookup brackets. There were no accommodations for automatic coupling. The heavy head assembly had to be manually lifted and its shank manually inserted into the receiver. A hitch pin had to be inserted through an opening in the receiver and the shank to secure the shank within the receiver. The chains, attached to the hookup brackets, had to be manually drawn up to an over-center position to properly tension the spring bars. The hookup brackets were locked in place by use of a retaining clip. All hardware had to be manually released, removed, and stored. The electrical connection between the trailer and the towing vehicle was done manually.
U.S. Pat. No. 3,649,046 to Mathisen, Mar. 14, 1972 shows a hitch with weight distributing spring bars; however, the spring bars had to be attached and detached manually. The heavy head assembly had to be removed manually. The electrical connection between the trailer and the towing vehicle was done manually. The towing vehicle was backed up to the trailer and the operator of the towing vehicle had to align the trailer tongue socket directly onto the ball; this required considerable skill and experience.
U.S. Pat. No. 4,606,549 to Williams, Aug. 19, 1986 shows a hitch which allowed a trailer to be automatically coupled to a towing vehicle. However, in this device, manual intervention was required for uncoupling. Further, it required that the latch pin be manually reset in order to allow for recoupling. The electrical connection between the trailer and the towing vehicle was done manually. There was no accommodation for weight distributing means.
U.S. Pat. No. 4,666,177 to Vinchattle, May 19, 1987 shows a receiver system with a four-sided funnel or hopper-shaped tongue bar guide comprising top and bottom immovable plates, rigidly secured to the top and bottom edges of the housing, and movable opposed side plates, each hingedly secured to opposed sides of the housing so as to be separately movable away from and into abutment with the top and bottom plates. A spring-loaded hitch pin engaged the tongue shank which in turn engaged a locking assembly. However, manual intervention was necessary for uncoupling. The electrical connection between the trailer and the towing vehicle was done manually. This device did not allow movement of the pulled vehicle as to yaw and pitch. Also, it required a spring to operate the receiver opening, causing considerable stress on the spring mechanism while in tow. There was no accommodation for weight distributing means.
U.S. Pat. No. 4,844,497 to Allen, Jul. 4, 1989 shows a hitch with a funnel-like receiver on the towing vehicle, using a spring-urged latch pin for joining the tongue shank and receiver. Even though it does provide for a semi-automatic release, manual intervention to release the latch pin was necessary. This device did not use a conventional ball and ball mount and therefore, would require excessive manufacturing tooling as it is not compatible with current, state of the art, weight distributing apparatus. The electrical connection between the trailer and the towing vehicle was done manually.
Mathisen and Reese both offer weight distributing hitches using spring bars, draw chains, and hookup brackets; however, both of these systems, although effective and usable, have several disadvantages:
a. The head assembly, which must be removed and replaced in both these systems is bulky, awkward, and heavy. PA0 b. The electrical connection between the two vehicles must be done manually. PA0 c. The spring bars, while being tensioned or relaxed, are under great stress and can cause severe hand injury when the hookup handle is thrusted to the ground or when the hookup handle disengages from the chain hook of the bracket and flings upward. Utmost caution must be practiced during this procedure. PA0 d. Separate operations are necessary in securing and releasing the trailer from the towing vehicle. PA0 a) reduces physical risk to the operator; PA0 b) facilitates faster coupling and uncoupling; PA0 c) eliminates the need to manually set and handle draw chains; PA0 d) eliminates the need to manually tension and release the spring bars; PA0 e) eliminates the need to remove and replace the head assembly and spring bars; PA0 f) reduces the possibility of equipment theft; PA0 g) eliminates the need to store a loose, heavy head assembly and spring bars; and PA0 h) provides an automatic electrical connection between the trailer and the towing vehicle.
These systems require excessive time, strength, and energy.